The Guardian Newspaper has posted its commenting guidelines for its own journalists.
I like them.
1. Participate in conversations about our content, and take responsibility for the conversations you start.
2. Focus on the constructive by recognising and rewarding intelligent contributions.
3. Don’t reward disruptive behaviour with attention, but report it when you find it.
4. Link to sources for facts or statements you reference, and encourage others to do likewise.
5. Declare personal interest when applicable. Be transparent about your affiliations, perspectives or previous coverage of a particular topic or individual.
6. Be careful about blurring fact and opinion and consider carefully how your words could be (mis)interpreted or (mis)represented.
7. Encourage readers to contribute perspective, additional knowledge and expertise. Acknowledge their additions.
8. Exemplify our community standards in your contributions above and below the line.